"Nudge" by Richard Thaler and Cass Sunstein explores the science of behavioral economics and its applications to public policy. The book argues that humans are not always rational decision-makers, and that understanding our cognitive biases can lead to better outcomes through interventions called "nudges". The authors propose libertarian paternalism, a philosophy where choices are framed in ways that encourage positive outcomes without restricting individual freedom. The book examines various domains where nudges can be applied, including retirement savings, health care, and climate change, and analyzes the effectiveness of different nudge strategies based on empirical data.